S5397 Autoimmune Hepatitis Post COVID-19 Vaccination: A Case Series

Introduction: Autoimmune hepatitis (AIH) is a rare but severe condition in which the immune system mistakenly targets liver cells, causing chronic inflammation and, if untreated, potentially leading to cirrhosis. Recently, cases of AIH following COVID-19 vaccination have raised concerns about the potential autoimmune side effects of these vaccines, though causal relationships remain uncertain. Initial reports suggest that COVID-19 vaccination may trigger or exacerbate AIH in predisposed individuals, highlighting a need for further investigation. This case series presents patients who developed AIH shortly after COVID-19 vaccination, detailing clinical presentations, serological findings, and therapeutic responses. Case Description/Methods: We present 4 cases of new-onset AIH following COVID-19 vaccination across a diverse demographic. Patient 1 is an 18-year-old man who developed symptoms 2 weeks post-Pfizer vaccine, presenting with jaundice, elevated liver enzymes, and positive autoimmune markers. Liver biopsy confirmed AIH, and the patient responded well to corticosteroids and azathioprine. Patient 2 is a 65-year-old woman who experienced acute hepatitis within days of receiving the Moderna vaccine. Her liver enzymes were significantly elevated, with positive smooth muscle antibodies, and she showed improvement with prednisone. Patient 3 is an 82-year-old woman with a history of hepatitis C who developed severe liver injury post-vaccination, with histology confirming AIH. Immunosuppressive therapy led to significant recovery. Patient 4 is a 35-year-old woman with known AIH in remission who experienced a flare 2 weeks after her second Pfizer dose, requiring increased immunosuppressive therapy. Discussion: AIH post-COVID-19 vaccination remains an uncommon but significant observation. Each case involved a temporal association between vaccination and onset of symptoms, raising questions of causality versus coincidence. Though vaccines may theoretically induce autoimmune conditions by molecular mimicry or immune system activation, the benefits of vaccination outweigh potential risks for most populations. However, these cases suggest a need for vigilant monitoring, particularly in individuals with known autoimmune predispositions. Whilst causation cannot be confirmed, these findings underscore the importance in post-vaccination monitoring for liver-related symptoms. Further research is warranted to elucidate underlying mechanisms and to determine whether specific vaccines or demographic factors increase susceptibility.